What is mechanical weathering?

The breakdown of rock without changing its chemical composition

What is chemical weathering?

The breakdown of rock by changing its chemical composition

What is mass movement?

Shifting of rocks and loose material down a slope which happens when the force of gravity acting on a slope is greater than the force supporting it

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What are destructive waves?

A high frequency (10-14 per minute) High and steepBackward is more powerful than their swash

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Formation of a wave cut platform

Waves cause erosion at the foot of the cliffThis forms a wave cut notch which is made bigger as erosion continues The rock above notch collapses This is washed away and a new wave cut notch starts to formThis being repeated results in cliff retreating A wave cut platform is left behind as cliff retreats

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Where do headlands and bays form?

Where erosion resistance is different

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The formation of caves, arches and stacks

Headland are made out of resistant rocks that are weakWaves crash into them and make the cracks bigger This is done by hydraulic action and abrasion Erosion continues and deepens the cave until it breaks through the headland forming an archEruption continues and wears away rock supporting arch until collapses this forms a stack

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What is longshore drift?

Waves go in the direction of prevailing wind Hit the coast at and an angle not a right angle The swash carries material up beach same direction of winds Backwash carries material down the beach at right angle and towards sea Zigzags along the coast

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Formation of a beach

Found at coasts between high water mark and low water markFormed by constructive waves depositing sand and shingle

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How do splits form?

Form at sharp bends in the coastline Longshore drift transports sand and shingle past the bend and deposits in the sea Waves and winds can curve the end of a spit The sheltered area behind the spit is protected from wavesMaterial collects there and plants grow Over time a marsh forms

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How are bars formed?

Formed when a split joins two headlands together The bar cuts off the bay between the headlands from the sea a lagoon can form behind the bar

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Why is sea level rising?

Because of global warming 2mm a year The rapid rise in global temperatures over the last 100 years Melting iceHeating oceans

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Coastal flooding impacts

Loss of tourism- cause tourist attractions to close and it can put people off visiting Loss of housing and jobs- people become homeless and certain coastal industries are shut down because of damage to equipment etc and jobs are lost Vegetation killed- the force of flood water uproots tees and plants

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Coastal flooding case study

The Maldives 300000 people 1.5 m above sea level

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Coastal erosion case study

Holderness From Flamborugh Head to Spurn Head1.8 m of land lost each year

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What were the impacts on the Maldives?

Loss of tourism- the main airport couldn't work because the flooding Less freshwater available- supplies of freshwater is already low and the sea is polluted and saltyLoss of beaches- wears away beaches on the islands at a rapid rate

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Impacts of coastal erosion (Holderness)

Homes near the cliffs are at risk of collapsing into the sea Property prices have fallenAccessibility has been affected as roads are near the cliffs

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Main reasons for rapid erosion

Easily eroded rock- made up of boulder clay which is easily erodedNaturally narrow beaches- less protection People worsening the situation- coastal defences called groynes have been built to stop material moving fighter down coast which means beaches are narrower

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Hard engineering methods

Sea wall- made up of hard material like concrete that reflects waves back to the seaRock armour- boulders that are piled up along the coast Groynes - wooden or stone fences that are built at right angles to trap material transported by longshore drift

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Soft engineering methods

Beach nourishment- sand and shingle from elsewhere that's added to beaches Dune regeneration- creating or restoring sand dunes by other nourishment or planting vegetation to stabilise the sand Managed treatment- removing existing defence and allowing the land behind it to flood

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Coastal habitat case study

Studland Bay (Dorset)Sand dunes BeachesHeathland

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What wildlife is found at Studland Bay?

Reptiles- have thick scaly skin to reduce water loss from their bodies Birds- Grebes are birds that dive underwater to find food in the sea with their feet far back to help them dive Plants- marram grass has folded leaves to reduce water loss because sand dunes are windy and dry